Man-made boards, such as fiberboard, e.g., hardboard, commonly are embossed downwardly on their intended visible major outer surface in the manufacture of interior paneling, exterior siding, and particularly in the manufacture of door skins, such that exterior surfaces, such as stiles and rails, are the highest structure of the embossed product. The prior art discloses that it is difficult to reverse mold and to emboss deep draws into a compressed wood fiber mat due to stretching and breaking of the fibers. Reverse molded fiberboard is stretched more on its visible outer surface than on its interior surface (surface in contact with a raised mold surface) making reverse molding much more difficult when attempting to provide sharp, crisp design detail in a raised panel that simulates natural wood millwork. As disclosed in the following U.S. patents, reverse molding and embossing deep draws into a fiberboard panel generally requires one or more of multiple press steps, post mold curing at elevated temperatures, a foil or high resin content outer surface portion, and/or high binder resin content of about 5-25%, preferably at least 10% by weight of the product: U.S. Pat. No. 4,061,813 Geimer; U.S. Pat. No. 4,378,265 Kiss; U.S. Pat. No. 4,552,797 Munk; U.S. Pat. No. 4,610,900 Nishibori; U.S. Pat. No. 4,612,224 Davis; 4,622,190 Schultz; U.S. Pat. No. 4,726,881 Schultz; U.S. Pat. No. 4,734,236 Davis; U.S. Pat. No. 4,812,188 Hansen; U.S. Pat. No. 4,844,968 Persson; U.S. Pat. No. 4,865,788 Davis; U.S. Pat. No. 4,960,548 Ikeda; U.S. Pat. No. 4,960,553 DeBruine; U.S. Pat. No. 4,969,302 Coggan; U.S. Pat. No. 5,028,374 Imao; U.S. Pat. No. 5,090,173 Coggan; U.S. Pat. No. 5,154,968 DePetris; U.S. Pat. No. 5,443,891 Bach; U.S. Pat. No. 5,851,325 Terada; U.S. Pat. No. 5,887,402 Ruggie.
The cellulosic fibers used to form the compressed mat, e.g., a one to two inch, preferably a ¾ to 1¾ inch thick layer of cellulosic fibers having a specific gravity (basis weight or pounds per square foot) of, for example, 0.6, initially may be bone dry after the fibers have been dried and felted, but the cellulosic fibers in such mats absorb moisture from the atmosphere and generally include about 2% to about 10% moisture when molded via hot pressing, depending upon the humidity in the region where such mats are stored and/or manufactured. The finished panels, after conditioning, have a moisture content of about 4½% to about 6½% by weight.
The reverse molded panels of the present invention are particularly suitable as wainscot panels and door skins, both for hollow core doors and as an added or plant-on feature to existing doors in order to enhance visual appearance. The panels are reverse molded to provide a “profile up” configuration. The reverse molding approach permits mounting the panel directly against a wall versus the prior art method requiring “shim spacers” (see FIG. 6A), thereby promoting easy installation while integrating excellent aesthetics of a wainscot panel. Historic treatments of real wood wainscot are well established and very expensive. Beyond the multiple piece millwork of real wood, some gypsum and polymeric materials have been fabricated into wainscot panels, but are marginally commercially acceptable, partly because they do not have the feel or look of natural wood. There are no wood fiber composite reverse molded wainscot systems available that provide the ease of application that is achieved in accordance with the principles of the present invention.